Removing surface fibers and lint

ABSTRACT

A product including a textile substrate and an image printed on the textile substrate in a predetermined area wherein surface fibers and lint are selectively removed from the textile substrate in the predetermined area by burning.

BACKGROUND

Substrates like textiles may have a surface morphology including surfacefeatures, such as lint or textile fibers on their respective surfaces.These substrate surface features may form an irregular surface structureor topography which may interfere with printing quality in direct totextile applications as these can interfere with and cause a printingfluid to be applied in a non-uniform layer on the irregular surface.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustration, certain examples will now be describedwith reference to the accompanying drawings, in which:

FIG. 1 shows a schematic illustration of a conditioning device accordingto an example in a top view;

FIG. 2 shows a schematic illustration of a radiation part of aconditioning device according to an example in a side view;

FIG. 3 shows a schematic illustration of a printer according to anexample in a top view;

FIG. 4 shows a schematic illustration of a product according to anexample in a top view;

FIG. 5 shows a schematic diagram illustrating a method according to anexample;

FIG. 6A shows a schematic diagram illustrating emitted power overwavelength of different radiation parts of various examples; and

FIG. 6B shows a schematic diagram illustrating absorption overwavelength of different absorbers of various examples.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings. The examples in the description and drawingsshould be considered illustrative and are not to be considered aslimiting to the specific example or element described. Multiple examplesmay be derived from the following description and/or drawings throughmodification, combination or variation of certain elements. Furthermore,it may be understood that also examples or elements that are notliterally disclosed may be derived from the description and drawings bya person skilled in the art. Whereas different examples are describedherein, it is understood that features of these examples may be usedindividually or in combination thereof to derive further variationsbeyond those explicitly describes herein.

A method and a device for conditioning a textile and a product includinga conditioned textile substrate are disclosed herein. Conditioning isprovided for selectively removing undesirable surface features which maycause surface obstructions, such as surface fibers and lint, from atextile substrate in an area to be printed on. The undesirable surfacefeatures may be removed selectively from the substrate by burning theundesirable surface features. This may be achieved by applying aconditioning fluid to the textile, the conditioning fluid having anabsorption spectrum differing from an absorption spectrum of the textilesubstrate. Then, the textile may be exposed to electromagneticradiation, such as ultraviolet (UV) or infrared (IR) radiation, having aradiation spectrum in a wavelength band matching the absorption spectrumof the conditioning fluid. The radiation spectrum and the absorptionspectrum of the conditioning fluid may match to such an extent thatradiation transforms into heat to burn off the undesirable surfacefeatures, such as lint and fibers because of their relatively lowthermal mass when compared to the bulk of the substrate. Heat is createdlocally where the conditioning fluid has been applied. The remainder ofthe textile, outside of the conditioned area, may remain unaffected. Thenon-conditioned area of the textile may have an absorption spectrumdifferent from that of the conditioning fluid so that the textile willnot be heated in the area free of the conditioning fluid, even ifirradiated in that area.

After removing undesirable surface features from the conditioned area, asmooth surface, free of fibers and lint, is obtained which provides anoptimal substrate for printing an image thereon.

FIG. 1 shows a schematic illustration of a conditioning device 100 in atop view. The conditioning device 100 comprises a printing part 1 and aradiation part 2. The radiation part 2 of the conditioning device 100according to an example is separately shown in FIG. 2 , in a side view.Reference is made to FIG. 2 where applicable. The printing part 1 andthe radiation part 2 as shown in FIG. 1 may be part of a single stage ora two stage conditioning device 100.

In the examples of FIG. 1 and FIG. 2 , the conditioning device 100provides a pretreatment of the substrate S to prepare a predeterminedarea A of the substrate S for printing an image, by selectively removingundesirable surface features L from the predetermined area A of thesubstrate S onto which printing will take place. The substrate S may bea textile, fabric or garment, for example, comprising natural fibers.Examples for natural fibers are wool, silk, camel hair, angora, cotton,flax, hemp, and jute. Examples of garments are T-shirts, sweaters,jackets, shorts and the like. A textile also may be provided in the formof a sheet or in the form of a continuous web which is fed from atextile supply roll. The pretreatment may be an operation to selectivelyremove lint and surface fibers from the substrate S to generate a smoothsurface area for printing.

In the examples of FIG. 1 and FIG. 2 , the substrate S to be treated,comprises a main substrate layer or bulk layer B and a surface layer L.The main substrate layer B includes bound or densely distributed fibersin a woven, non-woven, knitted or similar arrangement. The surface layerL may include loosely arranged or loose fibers or lint described hereinas undesirable surface features L or artifacts extending and/or formedfrom the main substrate layer B of the substrate S. Lint and fibersfurther may be considered part of the substrate S itself as theyoriginate from the material of the substrate S. In one example, a fiberdensity of the main substrate layer B is at least to times, or even atleast 20 or too times, higher than a fiber density of the surface layerL. Due to the difference in fiber density, the surface layer L has alower thermal mass than the main substrate layer B. For example, theratio of thermal mass between the main substrate layer B and the surfacelayer L is between to and too.

In the example of FIG. 1 , the printing part 1 of the conditioningdevice 100 may comprise a receiving surface 10 for receiving thesubstrate S and a print head, schematically shown at 12. The print head12 may be located in a carriage, such as a printer carriage or similarto a printer carriage. The receiving surface 10 may be a printer platenor may be similar to a printer platen. The substrate S is placed on thereceiving surface 10 between the print head 12 and the receiving surface10. The receiving surface 10 has a width in the x direction and a lengthin the y direction, as shown in FIG. 1 , with z designating the verticaldirection. In one example, dimensions of the receiving surface 10 may besuch that at least a substrate S of a size of a regular T-shirt may bereceived. For example, at least one of the width and the length of thereceiving surface 10 may be between 0.2 meters and 5 meters or between0.2 meters and 2 meters. In FIG. 1 , the length of the substrate S alsomay be defined in the y direction and the width may be defined in the xdirection. The receiving surface 10 may be substantially plane or flat.The substrate S is provided on the receiving surface 10 so as to providea substantially plane substrate surface on the receiving surface 10.

In the example of FIG. 1 , the printing part 1 may be to deposit aconditioning fluid on the substrate S within the predetermined area A.The predetermined area A is shown as a heart shape in FIG. 1 . Theprinting part 1 may have the configuration of or be similar to adrop-on-demand printer, including an inkjet-type print head, such as athermal inkjet or piezo-electric print head, for example. The printingpart 1 may comprise a 2-axis carriage. The 2-axis carriage comprises acarriage part for holding the print head 12, an x-axis guide bar 24 andtwo y-axis guide bars 26. The 2-axis carriage is to move the carriageincluding the print head 12 in two dimensions parallel to and above thesubstrate S and/or the receiving surface 10.

The x-axis guide bar 24 is to guide and move the carriage including theprint head 12 along the width direction x of the receiving surface 10.Further, the two y-axis guide bars 26 are to support the x-axis guidebar 24 and are to guide and move the carriage including the print head12 along the length direction y of the receiving surface 10. Further,the 2-axis carriage may comprise a drive unit and a control unit tocarry out and control the movement of the carriage. Thus, the print head12 may be arranged moveably in the x and y directions over the receivingsurface 10 by positioning the carriage. The print head 12 may be furtherarranged to be fixed in z direction over the receiving surface. Thus,the print head 12 may be to move in a plane parallel to the substrate S.

In one example, the print head 12 may be to scan along the widthdirection x of the receiving surface 10 by means of the x-axis guide bar24 across a strip portion of the substrate S between left- andright-hand boundaries (as shown in FIG. 1 ) of the predetermined area A.A strip portion may be defined as a row or swath printed along the widthdirection x of the receiving surface 10. During scanning, the print head12 may eject a conditioning fluid, as described further below. Theconditioning fluid thus is printed in a row or swath along the widthdirection x within the predetermined area A.

After scanning one strip portion and printing one swath of theconditioning fluid, the carriage including the print head 12 may bemoved along the length direction y of the receiving surface 10 in orderto arrange the print head 12 for printing a next strip portion betweenleft and right-hand boundaries of the predetermined area A. The nextstrip portion may be immediately adjacent to or overlapping with thepreceding strip portion. The offset between two subsequent stripportions may be in the range of 0.5 cm to 10 cm, e.g. in the order ofabout 0.5 cm, 1 cm or 2 cm, depending on the length of a nozzle array ofthe print head 12, for example. The scanning speed may be in the orderof 50-200 cm/s, for example. This procedure may be repeated until thepredetermined area A has been fully scanned by the print head 12, with anumber of swaths of conditioning fluid printed adjacent to each other orin an overlapping print mode. Printing in the x direction may beperformed both from left to right and from right to left (as seen inFIG. 1 ).

The printing of one strip portion may be performed in continuous swaths.During continuous printing, the print head 12 may continuously eject theconditioning fluid and scan across the substrate S to deposit theconditioning fluid within the predetermined area A.

In another example, the print head 12 may comprise a page wide print barhaving a nozzle array width spanning the width of the receiving surface10, also designated as page wide array, or a designated treatment areathereof. The page wide print head (not shown) can be provided on ay-axis carriage for movement in the y direction, for example, whereinthe y-axis carriage could be implemented using the two y-axis guide bars26 as shown in FIG. 1 . Printing a swath of conditioning fluid in the xdirection could be performed by sequentially or simultaneously printingthe conditioning fluid by the page-wide nozzle array between left- andright-boundaries of the predetermined area A of the substrate S.Printing subsequent swaths in the y direction can be performed by movingthe y-axis carriage in the y direction.

In a further example, the conditioning device 100 may comprise a feedmechanism to feed the substrate S in the form of a sheet or continuousweb through a printing zone, e.g. in the lengthwise direction y, withthe print head 12 located above the printing zone. The print head 12 maycomprise the page wide array or may be located on the x-axis guide bar24 supporting a carriage for printing in the x direction.

In the example, the conditioning fluid has an absorption band matchingwith a radiation band of the radiation source 30. In some examples, theradiation source 30 may be a commercially available emitter. Theconditioning fluid may be compatible with available printing technology,such as inkjet printing technology. In this case, a standard print headcan be used to eject the conditioning fluid and print the conditioningfluid in the predetermined area, following digital or analog printingmethodology in the same way as an image is printed.

In different examples, the conditioning fluid may be an ink including anelectromagnetic radiation-absorbing active material and an aqueous ornon-aqueous vehicle. The electromagnetic radiation-absorbing activematerial may be an IR light absorber, a near-infrared (NIR) lightabsorber, a plasmonic resonance absorber, a UV light absorber andcombinations thereof. These electromagnetic radiation-absorbing activematerials may be provided in the form of or may include a dye orpigments. In one example, the conditioning fluid includes pigmentedcarbon black ink and a transparent Tint Fluid agent to promoteabsorption in the IR band. In another example, the conditioning fluidmay include an additive to absorb energy at the radiation wavelengthranging from about 360 nm to about 410 nm to promote absorption in theUV band.

In one example, an IR light absorber includes a dispersion comprising ametal oxide nanoparticle having the formula MmM′On wherein M is analkali metal, m is greater than 0 and less than 1, M′ is any metal, andn is greater than 0 and less than or equal to 4; a zwitterionicstabilizer; and a balance of water. The metal oxide nanoparticles may bepresent in the dispersion in an amount ranging from about 1 wt % toabout 20 wt % based on the total weight of the dispersion. In some otherexample, the zwitterionic stabilizer may be present in the dispersion inan amount ranging from about 2 wt % to about 35 wt % (based on the totalweight of the dispersion). In yet some other examples, the weight ratioof the metal oxide nanoparticles to the zwitterionic stabilizer rangesfrom 1:10 to 10:1. In another example, the weight ratio of the metaloxide nanoparticles to the zwitterionic stabilizer is 1:1. For example,M can be an alkali metal like lithium (Li), sodium (Na), potassium (K),rubidium (Rb), cesium (Cs), or mixtures thereof.

In one example, NIR absorbing dyes or pigments may include anthroquinonedyes or pigments, metal dithiolene dyes or pigments, cyanine dyes orpigments, perylenediimide dyes or pigments, croconium dyes or pigments,pyrilium or thiopyrilium dyes or pigments, boron-dypyromethene dyes orpigments, or aza-boron-dipyrromethene dyes or pigments.

In one example, a plasmonic resonance absorber may comprise an inorganicpigment. The inorganic pigment may comprise lanthanum hexaboride (LaB₆),tungsten bronzes (A_(x)WO₃), indium tin oxide (In₂O₃:SnO₂, ITO),antimony tin oxide (Sb₂O₃:SnO₂, ATO), titanium nitride (TiN), aluminumzinc oxide (AZO), ruthenium oxide (RuO₂), silver (Ag), gold (Au),platinum (Pt), iron pyroxenes (A_(x)Fe_(y)Si₂O₆), modified ironphosphates (A_(x)Fe_(y)PO₄), modified copper phosphates(A_(x)Cu_(y)PO₂), modified copper pyrophosphates (A_(x)Cu_(y)P₂O₇), andcombinations thereof.

In one example, a UV light absorber may be an inkjet fluid having anadditive to absorb energy at the radiation wavelength ranging from about360 nm to about 410 nm. The additive may be selected from the groupconsisting of a compound containing from 3 to 5 fused benzene rings anda coumarin derivative. The ink further my include a co-solvent andwater, for example.

In the example of FIG. 2 , the radiation part 2 of the conditioningdevice 100 may be to expose the substrate S to electromagnetic radiationR, in particular the predetermined area A imprinted with theconditioning fluid. In particular, the radiation part 2 is to illuminatethe substrate S after the predetermined area A has been imprinted withthe conditioning fluid. The radiation part 2 may include a radiationsource 30, such as a lamp, which is stationary above the conditioningsurface 10 or which can be moved in the y direction or in the x and ydirections, similar to the movement of the printhead 12, to align theradiation source 30 with the treated predetermined area.

The radiation source 30 may comprise a single emitter such as an LED,for example, or it may comprise an array of emitters, such as LED orother light sources. The LED may be an UV-LED or an IR-LED, for example.The radiation source 30 is provided at a distance G from the substrateS. The radiation part 2 may be to radiate light in a predefined orpreset wavelength band, for example UV-A, UV-B, UV-C, IR or NIR band.The arrows below the lamp 30 illustrate a possible direction of lightfor illuminating the substrate S.

For example, when using a conditioning fluid having an IR lightabsorber, the wavelength of the radiation source 30 can be in the rangeof 780 nm to 1 mm. When using a conditioning fluid having an NIR lightabsorber, the wavelength of the radiation source 30 can be in the rangeof 780 nm to 3 μm. When using a conditioning fluid having a plasmonicresonance absorber, the wavelength of the radiation source 30 can be inthe range of 100 nm to 410 nm. When using a conditioning fluid having aUV light absorber, in particular UV-A, UV-B and UV-C, the wavelength ofthe radiation source 30 can be in the range of 315 nm to 410 nm, 280 nmto 315 nm and 100 nm to 280 nm, respectively.

The radiation source 30, in general, emits light at a spectral bandaligned with a maximum absorption band of the conditioning fluid.Exposure time and radiation energy are selected so as to sufficientlyheat the undesirable surface features L, such as fibers and lint, toburn the undesirable surface features L but not the bulk layer B ofsubstrate S. The conditioning fluid and the radiation band are selectedsuch that radiation does not impact the non-conditioned portion of thesubstrate S. For example, the absorption band of the substrate S and anydyes used for pre-coloring the substrate S may be lower than are outsideof the radiation band of the radiation source 30.

In one example, an exposing time may be ranging from about 0.1 secondsto about 20 seconds, or from about 0.1 seconds to about 5 seconds. Toachieve a desired amount of heating at the predetermined area A, powersettings of the radiation part 2 may be adapted. A power setting mayrange from about 3.5 W/cm² to about 10 W/cm². The power setting maydepend on the type of substrate, type of radiation source 30, theconditioning fluid and/or the distance G. In consequence, an energyexposure may range from about 0.5 J/cm² to about 20 J/cm², for example.

In one example, the substrate S has a radiation absorption pattern.Further, the conditioning fluid has another different radiationabsorption pattern. For example, the radiation absorption pattern of thesubstrate S and the radiation absorption pattern of the conditioningfluid may have maxima in respectively different wavelength bands. In oneexample, the radiation absorption pattern of the substrate S has aminimum in a wavelength band where the radiation absorption pattern ofthe conditioning fluid has a maximum. Similarly, the radiationabsorption pattern of the substrate S may have a maximum in a wavelengthband where the radiation absorption pattern of the conditioning fluidhas a minimum. When depositing the conditioning fluid on the substrateS, the radiation absorption pattern of the part of the substrate Streated with the conditioning fluid will be modified and may become thesame as or close to the radiation absorption pattern of the conditioningfluid.

In general, in the examples of FIG. 1 and FIG. 2 , the pretreatmentoperation may comprise providing the predetermined area A of thesubstrate S with the conditioning fluid and exposing the substrate S toradiation. The radiation has a wavelength band which matches with amaximum of a radiation absorption pattern of the conditioning fluid butnot with a radiation absorption pattern of the substrate S.

Accordingly, the radiation source 30 can be selected such that anemission power pattern of the radiation source matches with theradiation absorption pattern of the conditioning fluid. For example, theradiation source 30 can be further selected such that its emission powerpattern does not match with the radiation absorption pattern of thesubstrate S itself. Consequently, the radiation source 30 may be toexpose the substrate S to electromagnetic radiation having a wavelengthband which matches with a maximum of the radiation absorption pattern ofthe conditioning fluid to selectively remove the undesirable surfacefeatures L from the substrate S in the predetermined area A.

Once, the predetermined area A of substrate S is printed with theconditioning fluid and exposed to radiation, the radiation R istransformed into heat and constituents of the surface layer L, inparticular lint and fibers, within the predetermined area A of thesubstrate S are burnt due to their lower thermal mass compared to thefibers in the main substrate layer B. The radiation power of theradiation part 2 and/or the exposure time to radiation by the radiationpart 2 may be controlled in order to control the amount of heat locallygenerated for burning of the undesirable surface features L and to notaffect the main substrate layer B. The main substrate layer B henceremains substantially unaffected.

The conditioning device 100 as described with respect to FIG. 1 may be astand-alone device to which the substrate S is supplied and from whichthe substrate S is taken after processing. In another example, theconditioning device 100 may be part of a processing line wherein it maybe located upstream of a printer 3, which is described below withreference to FIG. 3 , for example. An advance direction of the substratethrough the processing line is shown by arrow P in FIG. 1 and arrow P′in FIG. 3 . In still a further example, the conditioning device 100 canbe integrated in a printer. If the conditioning device 100 is integratedinto a printer, a printer carriage and carriage drive mechanism can beused to support and scan a print head to eject conditioning fluid. Theradiation source 30 can also be supported by the printer carriage or canbe installed at a fixed position in the printer above a print zone. Thesubstrate S to be processed can be located on a printer platen. If thesubstrate S is a continuous material web, a printer feed mechanism canbe used to transport the substrate through a print zone.

In FIG. 1 , the radiation part 2 of the conditioning device 100 and theprinting part 1 of the conditioning device 100 are shown as separateunits by way of example. Nevertheless, the radiation part 2 and theprinting part 1 may be integrated in a single unit.

In one example, the radiation part 2 may be arranged downstream of theprinting part 1. In this example, the substrate S may be provided in theform of a sheet or continuous web that is fed in the lengthwisedirection y through a printing zone and an illumination zone, with theprinting part 1 located above the printing zone and the radiation part 2located above the illumination zone. In another example, the radiationpart 2 may comprise a 2-axis carriage similar to or the same as the2-axis carriage of the printing part 1. Thus, in different examples, theradiation source 30 may be static or movably arranged in x and/or ydirection of the receiving surface 10 so as to scan across theillumination zone in x- and/or y-direction of the receiving surface 10.

In one example, the radiation source 30 may comprise a page wide lamp ora page wide array of lamps. The page wide lamp or the page wide array oflamps may be to simultaneously or successively radiate light at thesubstrate S.

A radiation power of the radiation source 30 may be set depending on adistance G between substrate S and the radiation source 30 and/or a sizeof the substrate area to be exposed to radiation. The radiation powermay range from about 3.5 W/cm² to about 10 W/cm². Further, an exposuretime may be set from about 0.1 seconds to about 20 seconds, for example.

An exposure time may be set by controlling the speed of the feedingmechanism for the sheet or the continuous web in lengthwise direction ythrough the illumination zone. The speed may be set such that the timefor running the substrate S through the illumination zone ranges fromabout 1 seconds to 20 seconds. In another example, the sheet or thecontinuous web may be stationary such that the radiation source 30 ofthe radiation part 2 may be to scan across the substrate S for anexposure time of about 1 seconds to 20 seconds.

In the example where the radiation part 2 is implemented with theprinting part 1 in a single unit, the printing zone and illuminationzone may at least overlap or coincide. In one example, the carriage partfor supporting the print head 12 may also support the radiation part 2.In another example, the radiation part 2 may be statically arranged inthe conditioning device. The radiation part 2 may be to radiate lightduring printing of the conditioning fluid. Further, the radiation part 2may be arranged upstream of the printing part 1 in the same unit. Thus,the radiation part 2 can follow a scanning movement of the printing part1, thereby illuminating parts of the substrate S which have beenconditioned.

FIG. 3 shows a schematic illustration of a printing device 3 accordingto an example in a top view. Reference is made to FIGS. 1 and 2 , whereapplicable. The printing device 3 may comprise a printer platen 50, aprint head 42, an x-axis guide bar 44 and two y-axis guide bars 46. Theprinting device 3 may be equal or similar to the printing part 1 of theconditioning device 100 as described with respect to FIG. 1 . Thus, fordetails regarding the printing device 3, reference is made to FIG. 1 .Further, the carriage can support a print head 42 to print a coloredprinting fluid on the predetermined area A′ of the substrate S. Thepredetermined area A′ may correspond to the predetermined area A of thesubstrate S according to FIGS. 1 and 2 after conditioning thepredetermined area A of the substrate S and exposing the substrate S toelectromagnetic radiation to selectively remove undesirable surfacefeatures L, such as lint and fibers.

FIG. 4 shows a schematic illustration of a product 4 according to anexample in a top view. The product 4 includes a textile substrate S andan image printed on the textile substrate S in a predetermined area A″.The predetermined area A″ may correspond to the predetermined areas Aand A′ after printing the colored printing fluid on the predeterminedarea A′. In particular, surface fibers and lint are removed from thetextile substrate S in the predetermined area A″ by burning. Since, thesurface fibers and lint have been burnt, a surface of the substrate S inthe predetermined area A′ is flat and smooth. Thus, an image printed inthe corresponding predetermined area A″ may have a uniform constitution.The product 4 may be an organic or inorganic textile fabric in the formof a finished article, such as clothing, blankets, tablecloths, napkins,towels, bedding materials, curtains, handbags, shoes, banners, signs,flags or similar articles.

FIG. 5 shows a schematic diagram illustrating a method according to anexample. Reference is made to FIGS. 1 to 4 , where applicable. Themethod comprises providing a substrate S which has a maximum ofradiation absorption at a first wavelength band, at 110.

Further, the method comprises depositing, on a predetermined area A ofthe substrate S, a conditioning fluid which has a maximum of radiationabsorption at a second wavelength band, at 120. In one example,depositing 120 the conditioning fluid includes printing the conditioningfluid. Accordingly, the radiation absorption of the substrate S in thepredetermined area A is adjusted to the radiation absorption of theconditioning fluid by printing the conditioning fluid in thepredetermined area A of the substrate S.

Further, the method comprises exposing the substrate S toelectromagnetic radiation at the second wavelength band to removeundesirable surface features L from the predetermined area A of thesubstrate S, at 130. The undesirable surface features may be removed byburning. The first wavelength band differs from the second wavelengthband. For example, the second wavelength band may be a near infrared,NIR, band, or an ultraviolet, UV, band. Further, the second wavelengthband may be in an ultraviolet, UV, band. For example, the UV band may bethe UV-A band.

In one example of FIG. 5 , the depositing 110 the conditioning fluid onthe predetermined area A and exposing 130 the substrate toelectromagnetic radiation are performed successively.

In one example of FIG. 5 , the method further comprises printing on thepredetermined area A of the substrate S with a colored printing fluidafter printing 110 the conditioning fluid on the predetermined area A ofthe substrate S, at 140. Further, the printing 140 may be performedafter selectively removing undesirable surface features L from thepredetermined area A of the substrate S, at 130.

In one example of FIG. 5 , the electromagnetic radiation has more than80% of its power in the second wavelength band and less than 20% of itspower in the first wavelength band. In the same or another example, anabsorption of a part of the substrate S free from conditioning fluid islower than 40% in the second wavelength band and higher than 40% in thefirst wavelength band. In the same or yet another example, an absorptionof a part of the substrate S treated with the conditioning fluid ishigher than 40% in the second wavelength band and lower than 40% in thefirst wavelength band.

FIG. 6A shows a schematic diagram illustrating emitted power overwavelength of different radiation sources 30. Reference is made to FIGS.1 to 4 , where applicable. In particular, FIG. 6A shows two differentgraphs F1 and F2 respectively representing emitted power over wavelengthfor different lamps used as radiation source 30. On the axis ofordinates, an electrical power is shown in kW. On the axis of abscissa,a wavelength is shown in nm.

In the example of FIG. 6A, the graph F1 represents the emitted powerover wavelength of a halogen IR lamp. The graph F1 shows that theradiated power of the halogen IR lamp has a maximum in the NIR band, i.eat about 1200 nm. In particular, more than 90% of the power radiated bythe halogen IR lamp may be radiated within the NIR band. The rest of thepower may be radiated in neighboring bands, for example in bands havinglarger wavelengths and lower frequencies. In this example, the maximumpower is at about 90 kW.

In the example of FIG. 6A, the graph F2 represents the emitted powerover wavelength of a ceramic IR lamp. The graph F2 shows that theradiated power of the ceramic IR lamp has a maximum outside the NIRband. In particular, more than 90% of the power radiated by the ceramicIR lamp may be radiated outside the NIR band, for example in bandshaving larger wavelengths—lower frequencies. Less than 10% of the powermay be radiated in the NIR band.

FIG. 6B shows a schematic diagram illustrating absorption overwavelength of different absorbers which may be used in a conditioningfluid. Reference is made to FIGS. 1 to 4 , where applicable. Inparticular, FIG. 6B shows two different graphs F3 and F4 respectivelyrepresenting absorption of power over wavelength for the conditioningfluid and the substrate S. On the axis of ordinates, an absorption isshown in percent. On the axis of abscissa, a wavelength is shown in nm.

In the example of FIG. 6B, the graph F3 represents the absorption overwavelength of a substrate S or a predetermined area A of the substrate Sbeing treated with an electromagnetic radiation-absorbing activematerial in a conditioning fluid to shift the absorption of thesubstrate S towards the NIR band. In particular, the electromagneticradiation-absorbing active material may be an NIR light absorber in theform of or may include a dye or pigments. For example, the NIR lightabsorber may include anthroquinone dyes or pigments, metal dithiolenedyes or pigments, cyanine dyes or pigments, perylenediimide dyes orpigments, croconium dyes or pigments, pyrilium or thiopyrilium dyes orpigments, boron-dypyromethene dyes or pigments, oraza-boron-dipyrromethene dyes or pigments.

In particular, it may be assumed that the absorption of the conditioningfluid and the absorption of the treated substrate S are the same orapproximately the same. In the example of FIG. 6B, the conditioningfluid may be pigmented carbon black ink or low tint fluid agent which istransparent. The graph F3 shows that the absorption of the carbon blackink has a maximum in the NIR band and a minimum in neighboring bands ofthe NIR band, for example in bands having larger wavelengths and lowerfrequencies. For example, the absorption in the NIR band may be higherthan 35%, wherein an absorption in neighboring bands may be lower than35%.

Generally, the conditioning fluid may be selected to match a wavelengthradiation pattern of a radiation source 30 shown in FIG. 6A as graph F1.Alternatively, the radiation source 30 shown in FIG. 6A as graph F1 maybe selected to match a radiation absorption pattern over wavelength ofthe conditioning fluid shown in FIG. 6B as graph F3.

In the example of FIG. 6B, the graph F4 represents the absorption overwavelength of the substrate S free of any conditioning fluid. The graphF4 shows that the absorption of the substrate S has a maximum outsidethe NIR band. In particular, an absorption of the substrate S in the NIRband may be lower than about 35%.

Substrate portions free of any conditioning fluid may have a radiationabsorption which may increase with wavelength, as shown in the graph F4of FIG. 6B. Correspondingly, the conditioning fluid may be selected sothat the radiation absorption of the conditioning fluid maysubstantially decrease with wavelength. Thus, the conditioning fluid maybe selected so as to have a radiation absorption with a maximum in anNIR band or other defined wavelength bands, such as the UV band,depending on the radiation source to be used.

Experiments have shown that the method and device described herein cansafely remove lint and surface fibers from a textile substrate withoutdamaging the bulk of the substrate. In the treated area the texture ofthe substrate can be perceived more clearly. The method and device canbe selective in that portions of the substrate not to be treated remainunaffected. For example, a soft and “hairy” textile will preserve itssoft touch and feel outside of treated areas. Further, the method iscompatible with most features and protrusions of the substrate, such asknitting patterns, decorative stitching, ornamental or functional seams,buttons, appliqués and the like.

The result of the treatment is very uniform and provides a smooth andflat surface suitable for printing an image thereon. The processing timeis relatively low, such as less than two minutes, depending on the sizeof the area to be treated. Treatment consumes little energy and onlylittle resources, such as a limited amount of conditioning fluid printin the predetermined area. Costs and complexity are low.

Further, the conditioning device 100 can be integrated in a printer andmake use of printer equipment, such as a substrate holding mechanism,substrate feed mechanism, printing mechanism and a carriage mechanism.The conditioning fluid may be handled like ink.

The statements set forth herein under use of hardware circuits, softwareor a combination thereof may be implemented. The software means can berelated to programmed microprocessors or a general computer, an ASIC(Application Specific Integrated Circuit) and/or DSPs (Digital SignalProcessors). Whereas some details have been described in terms of acomputer-implemented method, these details may also be implemented orrealized in a suitable device, a computer processor or a memoryconnected to a processor, wherein the memory can be provided with one ormore programs that perform the method, when executed by the processor.

1. A method, the method comprising: providing a substrate which has amaximum of radiation absorption at a first wavelength band; depositing,on a predetermined area of the substrate, a conditioning fluid which hasa maximum of radiation absorption at a second wavelength band; exposingthe substrate to electromagnetic radiation at the second wavelength bandto selectively remove undesirable surface features from thepredetermined area of the substrate; and wherein the first wavelengthband differs from the second wavelength band.
 2. The method according toclaim 1, wherein the substrate is a textile and the undesirable surfacefeatures are lint or surface fibers.
 3. The method according to claim 1,wherein the second wavelength band is a near infrared, NIR, band.
 4. Themethod according to claim 1, wherein the second wavelength band is anultraviolet, UV, band.
 5. The method according to claim 1, whereindepositing the conditioning fluid includes printing the conditioningfluid.
 6. The method according to claim 5, wherein the radiationabsorption of the substrate in the predetermined area is adjusted to theradiation absorption of the conditioning fluid by printing theconditioning fluid in the predetermined area of the substrate.
 7. Themethod according to claim 5, further comprising: printing on thepredetermined area of the substrate with a printing fluid after printingthe conditioning fluid on the predetermined area of the substrate. 8.The method according to claim 1, wherein depositing the conditioningfluid on the predetermined area and exposing the substrate toelectromagnetic radiation are performed successively.
 9. The methodaccording to claim 1, wherein the second wavelength band is in anultraviolet, UV, band.
 10. The method according to claim 1, wherein theelectromagnetic radiation has more than 80% of its power in the secondwavelength band and less than 20% of its power in the first wavelengthband.
 11. The method according to claim 1, wherein an absorption of thesubstrate free from conditioning fluid is lower than 40% in the secondwavelength band and higher than 40% in the first wavelength band. 12.The method according to claim 1, wherein an absorption of the substratetreated with the conditioning fluid is higher than 40% in the secondwavelength band and lower than 40% in the first wavelength band.
 13. Aconditioning device; the conditioning device comprises: a printing partto print, on a substrate, a conditioning fluid having a radiationabsorption pattern over wavelength; a radiation part to expose thesubstrate to electromagnetic radiation having a wavelength band matchingwith a maximum of the radiation absorption pattern to selectively removeundesirable surface features from the substrate.
 14. The preconditioningdevice according to claim 13, wherein the radiation part is an infrared,IR, emitter.
 15. A product including a textile substrate and an imageprinted on the textile substrate in a predetermined area wherein surfacefibers and lint are removed from the textile substrate in thepredetermined area by burning.